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(No Model.) Y 3 Sheets-Sheeig'l.

T. M. NORTH.

AIR GUSHIONING DEVICE I'OR PRINTING PRESSES.

No. 600,164. Patented Mar. 8, 1898 (No Model.) 3 Sheets-Sheet 2. T. M.NORTH.

AIR CUSHIONING DEVICE FOR PRINTING PRESSES.

N0. 600,164. Patented Mar. 8,1898.

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(No Model.) 3 Sheets-Sheet 3.

T. M. NORTH.

AIR CUSHIONING DEVICE POR PRINTING PRESSES.

N0. 600,164. Patented Mar. 8, 1898.

ea f77/vena?" UNITED STATES PATENT OFFICE.

THOMAS M. NORTH, OF BROOKLYN, NEW YORK, ASSIGNOR TO ROBERT HOE, THEODOREH. MEAD, AND CHARLES W. CARPENTER, OF NEW YORK, N. Y.

AIR-CUSHIONING DEVICE FOR PRINTING-PRESSES.

SPECIFICATON forming part of Letters Patent No. 600,164, dated March 8,1898.

Application filed December 26, 1895. Serial No. 573,299. (No model.)

To all whom, t may concern:

Be it known that I, THOMAS M. NORTH, a subject of the Queen of GreatBritain, residing at Brooklyn, county of Kings, and State of New York,have invented certain new and useful Improvements in Air-CushioningDevices for Printing-Machines, fully described and represented in thefollowing specification and the accompanying drawings, forming a part ofthe same.

This invention relates to air-cushionin g devices which operate tocontrol the suspending or arresting of the movement 0f the reciprocatingbed of a bed-and-cylinder printing-machine at the end of its stroke.

The object of the invention is to provide an improved safety or reliefvalve construction for such air-cushioning devices which is controlledby the connecting and disconnecting of the press to and from thedriving-shaft, so as to permit the relief-valve to o pen at a lowerpressure when the bed is released from the driving-shaft.

The invention consists in the construction and arrangement of the valve,as is hereinafter fully explained and claimed.

A practical embodiment of the invention is illustrated in theaccompanying drawings, wherein- Figure 1 represents a side elevation,partly in section, of so much of a bed-and-cylinder printing-machine asis necessary to illustrate the same. Fig. 2 is an end elevation thereofas seen looking in the direction of the arrow 2 in Fig. 1. Fig. 3 is anenlarged longitudinal sectional elevation of one of the air-cylinderswith the piston at one end of its stroke; and Fig. 4 is a similar viewof a portion of the same cylinder, showing the piston at the other endof its stroke. Fig. 5 is an elevation, partly in section, of the relief-valve mechanism; and Fig. 6 is a plan view of the relief-valve.

The printing mechanism shown consists of a revolving impression-cylinderA and a cooperating reciprocating type-carrying bed B, the means foroperating this printing-couple being omitted as unnecessary, it beingunderstood that the improvements herein contained are applicable to anyprinting-machine having a reciprocating type-carrying bed.

In the practical embodiment of the machine shown the bed B isillustrated as provided with four air-cylinders,two of the four, as seenfrom the side of the machine, being shown in Fig. 1 and marked,respectively, 2 4, and two at the end of the machine, being shown inFig. 2, the same being marked 2 3. These cylinders are supported by theframework, as is usual, and have their mouths or open ends pointingtoward the center of the machine, so that the same may receive thepistons 1, which are rigidly attached to the bed, travel with the same,and enter the open end of the cylinder at each end of the bed andmovetherein, compressing the air to afford resistance, which aids inbringing the bed to a stop, as is common and well understood.

The aircylinders are provided with irnproved valves, which are soconstructed that they will normally stand open and yet may readilyperform their function of closing the cylinders. Referring moreparticularly to Fig. 3, these air-cylinders will be found provided attheir outer ends with a head 10, centrally perforated with anair-passage 11 and having a central interior projecting pipe whose innerface is cut at an oblique angle to form the valve-seat. A rib 12 alongthe upper portion of this central projection affords a hanger for thevalve proper, which is a circular plate 13, faced with a leather packing14:, said plate 13 having a lever 15 connected with it at such an anglethat this lever 15 bears upon the inner projection 11, so that the valvepivoted at 16 to the rib 12 will hang and rest in the position shown inFig. 3 or be lifted and closed, as in Fig. 4.

In Fig. 3 the piston 1 is just entering the cylinder 2, moving in thedirection of its associated arrow, at which time the flap-valve is, inconsequence of its gravity, hanging so as to open the aperture 11.

In the ordinary course of the operation of the machine, when the same isrunning at speed, the bed will carry this piston 1 rapidly into thecylinder 2, and, compressing the air therein,will force the flap-valveclosed, so

that a continuously-increasing and higher pressure of the air condensedtherein may be exerted against the movement of the bed. By this simplestructure the parts may be turned over by hand in making ready, dac., ata low speed, which will not move the piston 1 rapidly enough into thecylinder 2 to cause the flap-valve to close, and hence any moderatepressure of air Within the cylinder will not be suicient to obstruct theready movement of the machine by hand.

The air-cylinders are provided with a safety or relief valve embodyingthe present invention, as follows: Between the head of each cylinder andthe inward point thereof reached by the piston in its stroke, as seen inFig. 4, each cylinder is provided with a pipe 20,that leads to arelief-valve,which is provided with a weight capable of adjustment todetermine the pressure at which said valve shall open. In thisembodiment of it said valve consists of a head 22, provided with acushion 25, a stem 21, and wings 23, by which it is guided vertically.This stem 2l rests upon a lever 27, whose pivot is in an arm 24,projecting from one side of the pipe 20, and upon the long arm of thislever there is arranged a sliding weight 26. By setting this weight 26at any suitable position upon the lever 27 its pressure resisting theopening of the valve 22 maybe increased or diminished, as desired, andhence the pressure of the compressed air in the air-cylinders necessaryto move the lever and thus open the relief-valve is determined and maybe regulated.

Herein the weight 26 is attached to the beltshifter 40 by means of anarm 4l, pivoted to an arm 42, that, through a rock-arm 8 and rod 43, ispivoted to said shipping-lever 40. In Fig. 2 the shipping-lever isthrown to carry the driving-belt onto the loose pulley, at which timethe machine will stop. As that arrangement is advantageous, theadjustment of the weight 26 with respect to its carryinglever 27 may bemade by a means for adjusting the rod. 4l in its connection with the arm42, so that the desired relation of the weight 26 on the lever 27 may behad when the machine is operating and said weight be drawn near to thepivot of the lever 27 when the machine is to be stopped, the desiredpressure against the opening of the relief-valve being thus maintainedwhen the machine is running and that pressure minimized when the machineis to be stopped.

Vhen in the ordinary operation the machine is suddenly stopped by movingthe beltshifter to throw on the driving-belt, the bed will continue totravel by reason of the m0- mentum of the moving parts, thus causing theplungers to enter the air-cylinders at such speed and with such force asto compress the air therein to such an extent as to cause the bed torebound, which action frequently makes the machine break down. To avoidthis, the structure connecting the weight 26 with the shipping-leverisadvantageous, since when the shipping-lever is moved to stop the machineit withdraws said weight to a position on the lever 27 which causes itto exert the least resistance to the opening of the relief-valve, andhence adapts the air apparatus at such a time to the easy stoppage ofthe movement of the bed. In practice this sudden stoppage of the machinewhen necessary from any cause and performed by the movement of thebelt-shifter frequently takes place when the bed is near the end of itsstroke with the piston l in the cylinder, thus making it necessary inorder to protect the machine from damage that the air-pressure shall beimmediately relieved.

lVhat is claimed is- The combination With an air or cushioning cylinderfor the piston of a reciprocating bed, of a relief-valve connected by apipe to said cylinder, said valve being seated upon a lever providedwith an adjustable weight that is connected with the shipping-lever ofthe machine whereby it is moved on the lever on which the valve isseated, substantially as described.

In testimony whereof I have hereunto set my hand in the presence of twosubscribing Witnesses.

THOMAS M. NORTH.

Witnesses:

F. W. H. CRANE, E. L. SPEIR.

